From: Christoph Hellwig <hch@lst.de>
To: Coly Li <i@coly.li>
Cc: Christoph Hellwig <hch@lst.de>,
colyli@kernel.org, linux-raid@vger.kernel.org,
linux-block@vger.kernel.org, Yu Kuai <yukuai3@huawei.com>,
Xiao Ni <xni@redhat.com>, Hannes Reinecke <hare@suse.de>,
Martin Wilck <mwilck@suse.com>, Keith Busch <kbusch@kernel.org>
Subject: Re: [RFC PATCH] md: split bio by io_opt size in md_submit_bio()
Date: Wed, 16 Jul 2025 13:41:22 +0200 [thread overview]
Message-ID: <20250716114121.GA32207@lst.de> (raw)
In-Reply-To: <437E98DD-7D64-49BF-9F2C-04CB0A142A88@coly.li>
On Wed, Jul 16, 2025 at 07:39:18PM +0800, Coly Li wrote:
> >> For raid level 4/5/6 such split method might be problematic and hurt
> >> large read/write perforamnce. Because limits.max_hw_sectors are not
> >> always aligned to limits.io_opt size, the split bio won't be full
> >> stripes covered on all data disks, and will introduce extra read-in I/O.
> >> Even the bio's bi_sector is aligned to limits.io_opt size and large
> >> enough, the resulted split bio is not size-friendly to corresponding
> >> raid456 level.
> >
> > So why don't you set a sane max_hw_sectors value instead of duplicating
> > the splitting logic?
>
> Can you explain a bit more detail? In case I misunderstand you like I
> did with Kuai’s comments
Just set the max_hw_sectors you want.
next prev parent reply other threads:[~2025-07-16 11:41 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-15 18:02 [RFC PATCH] md: split bio by io_opt size in md_submit_bio() colyli
2025-07-16 1:46 ` Yu Kuai
2025-07-16 6:58 ` Yu Kuai
2025-07-16 8:50 ` Coly Li
2025-07-16 9:30 ` Yu Kuai
2025-07-16 11:37 ` Christoph Hellwig
[not found] ` <437E98DD-7D64-49BF-9F2C-04CB0A142A88@coly.li>
2025-07-16 11:41 ` Christoph Hellwig [this message]
2025-07-16 11:44 ` Coly Li
2025-07-16 11:45 ` Christoph Hellwig
2025-07-16 12:10 ` Coly Li
2025-07-16 12:14 ` Christoph Hellwig
[not found] ` <DE36C995-4014-44DC-A998-1C4FF9AFD7F9@coly.li>
2025-07-16 12:17 ` Christoph Hellwig
2025-07-16 12:23 ` Coly Li
2025-07-16 16:29 ` Yu Kuai
2025-07-17 4:52 ` Christoph Hellwig
2025-07-17 15:19 ` Coly Li
-- strict thread matches above, loose matches on Subject: below --
2025-07-15 17:59 colyli
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